HMPE Ropes:Benefits to the Trawl Industry

HMPE-Synthetic Wire RopeHMPE fiber rope has been effectively used as wire rope replacement for applications that require manual handling or reduced weight.Today’s Trawl Applications

Gilson LinesTrawl Net BridlesFraming RopesCod End Rib LinesLifting Straps

Presentation Overview

Current uses in Trawl industryHMPE wire rope replacementEconomic ValueBenefits over Tradition fiber ropes

HMPE Fiber PropertiesRope PropertiesRetirement

Major Uses of HMPE ropesWire Rope Replacement

Gilson LinesTrawl Net Bridles

Chain replacementCod End Rib Lines

Traditional Synthetic Rope Replacement

Framing ropes

Wire Replacement: Key benefit

Economic Value

HandlingRigging Hardware costsLongevityMiscellaneous

Economic Value: Handling.Size-for-Size

Economic Value: Handling.Weight

1” 12 Strand HMPE Rope

21.8 lbs for 100 feet

1” IWRC Wire Rope

185 lbs for 100 feet

Economic Value: HandlingWeight

Economic Value: Rigging CostsHardware

Reduction of components:

FlatlinksG-HooksHammerlocks

Elimination of components

Swivel Rollerbearing

Lifetime cost reduction

Economic Value: Longevity.TCLL Test Method

TCLL – Level of load that fatigues rope to break at the 1000th cycle

- fatigue resistance test

1. 50% of rope’s breaking strength – 1000 cycles2. 60% of rope’s breaking strength – 1000 cycles3. 70% of rope’s breaking strength – 1000 cycles.4. …..continue the procedure at 10% incremental of

breaking strength till rope breaks.

The results are then used to calculate a TCLL value which theoretically represents the load (expressed as a % of the breaking strength) at which the rope would fail at exactly 1000 cycles.

Economic Value: Longevity.TCLL Test Results

Economic Value: Longevity.

Economic Value: Longevity.Bending Fatigue (D/d = 25)

Economic Value: Miscellaneous

Lubricating wireDamage to the vessel

Wire Rope Replacement Economic Value:

Reduced InjuriesReduced crew fatigueReduced Seasonal Hardware costsIncreased lifetimeLess Maintenance

Traditional Rope Replacement.Key Benefits

Increased LifetimeWeightBetter Abrasion resistance

Abrasion Resistance

HMPE fibers

High Modulus Polyethylene FiberDyneema-DSM High Performance Fibers, The NetherlandsSpectra-Honeywell, USA

DyneemaSK-60SK-75

SpectraSpectra-900Spectra-1000

3.4

0.97

1300

35

1150

Spectra1000

3.63.64.4Elongation%

Cross-section

Densityg/cc

Weightdenier

Strengthg/denier

Modulusg/denier

0.970.970.97

160016001600

403227

12801020720

DyneemaSK-75

DyneemaSK-60

Spectra900

HMPE fiber properties

HMPE fiber ropesImportant Rope Properties

Strength• Initial Strength• Strength after usage

WeightAbrasion resistance

Measurements of Properties

Rope properties are a function of the test method used to measure them.

WeightRelaxed weightReference load weight

Initial Rope StrengthISO Standard-measures un-terminated rope strengthCI Standard-measures spliced rope strength

Measurements of Properties

Rope strength after usageAll material generally get weaker with use.

Abrasion TestingNot directly comparable to real world environments.Used to qualitatively compare materials

HMPE Fiber Ropes Properties:Initial Strength

Rope DesignRope ConstructionTwist LevelsPick AngleCoating

Optimize Construction for Application

HMPE Fiber Ropes Properties:Initial Strength

Post-ProcessingHeatTension

Increase strength up to 25% and reduce diameter by 20%

Post Processing Effects:Initial strength vs Longevity

Post Processing Effects:Initial strength vs Longevity

Rope Performance: Mechanisms influencing Longevity

New Rope:ConstructionProcessing

Used RopeAbrasionImpact/Shock LoadingDrum compressionCyclic fatigueInduced Twist

Effects of Abrasion

At t = 0

Reference 31.500 kg 100 %

At t = 4190 cycles @ 60% Reference

1. Drum layer 1 24.860 kg 79 %

2. Drum layer 2 24.260 77 %

3. Drum layer 3 26.610 84 %

4. Buried rope 26.750 85 %

5. Horizontal part 31.920 101 %

6. Bending point 30.550 97 %

Horizontal part = Tensile Fatigue not an issue

Effects of Tensile Fatigue

Develop Retirement Criteria

Retirement

Current Retirement: Gilson lines- 1-2 seasonsBridles- 4 seasonsFraming Ropes –Not defined (3+ seasons)

Retirement based on usage/residual strength

Conclusions

HMPE ropes provide sound economic value over wire rope.

Reduced InjuriesReduced crew fatigueReduced Seasonal Hardware costsIncreased lifetimeLess Maintenance

Not all HMPE fibers are the sameNot all HMPE ropes are created equalRetirement Guidelines based on usage